<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>box-shadow</title>
    <style>
        .container{
            background: red;
            width: 200px;
            height: 200px;
            margin: 100px;
            /* box-shadow: 5px 5px 10px 0 rgba(0, 0, 0, .2); */
             box-shadow: inset 5px 5px 10px 0 rgba(0, 0, 0, .2);  /*添加内阴影*/

        }
    </style>
</head>
<body>
    <div class="container"></div>
</body>
</html>
